1. Field of the Invention
The present invention relates to mold adjustment of an electromotive injection molding machine, and more particularly to a mold adjustment device of an injection molding machine, to which spherical bearings are mounted to solve the stoppage problem occurring during the mold adjustment operation.
2. Description of the Related Art
For mold adjustment in a conventional electromotive injection molding machine, a motor (not shown) rotates a ring gear 1 so that a tie bar gear 2 attached to the ring gear 1 is rotated, and accordingly a nut 3 inserted into a rear template 4 is rotated to move forward and rearward along a screw 51 of a tie bar 5, as shown in FIG. 1.
At this time, the nut 3 moves with pushing the rear template 4, thereby allowing mold adjustment.
In this conventional configuration, the tie bar gear 2 rotating along four tie bars 5 and the screws 51 of the tie bars 5 is directly contacted with the rear template 4, which may apply a clamping force to the tie bars 5, or the rear template may be twisted when another external force is applied thereto, which may make the tie bar gear 2 be engaged with the rear template 4. That is to say, the tie bar gear 2 moving along the tie bars 5 and the screws 51 of the tie bars 5 is directly contacted with the rear template 4, so the tie bar gear 2 directly receives a force applied toward the rear template 4 when this force is transmitted to the tie bars 5. At this time, if the rear template 4 is twisted, the tie bar gear 2 is engaged with the rear template 4 as shown in FIG. 2. Thus, when moving a position of the rear template for mold adjustment, the engagement between the tie bar gear 2 and the rear template 4 may disturb the mold adjustment process.
In case the tie bars or the rear template is bent due to the engagement shown in FIG. 2, a nut may also be held therein not to move. In order to solve this problem, there is needed a structure capable of relieving stress generated between the tie bars 5 and the rear template 4 during injection molding.
In addition, in case of a precise injection molding, more precise control is occasionally required.